Apparatus for casting metal articles

ABSTRACT

A mold having a bottom opening is secured to a car that is movable to and from a pouring tube that is engaged with a ladle of molten metal. The bottom opening and pouring tube are fluidly communicable through an ingate assembly that may be pivoted into airtight engagement with the mold assembly and lowered onto the pouring tube. After molten metal is passed into the mold through the ingate assembly and solidifies, the ingate assembly may be pivoted away from the mold assembly thereby breaking the metal in the ingate assembly away from the metal in the bottom opening.

United States Patent Ebeling [4 1 Mar. 28, 1972 [54] APPARATUS FORCASTING METAL ARTICLES [72] Inventor: Arthur W. Ebellng, Elmhurst, 111.

21 Appl. No.: 565,912

[52] 11.8. CI ..l64/339, 164/337 Takacs et a1. ..164/337 X 2,675,5844/1954 Fienberg et a1. ..25/D1G. 27 3,435,884 4/1969 Orris et a1 164/3412,963,308 12/1960 Valentyne et a1 ..,.74/1 10 X FOREIGN PATENTS ORAPPLICATIONS 851,662 10/1952 Germany 164/306 Primary Examiner-Robert D.Baldwin Attorney-Walter L. Schlegel, Jr. and Spencer L. Blaylock, Jr.

[ ABSTRACT A mold having a bottom opening is secured to a car that ismovable to and from a pouring tube that is engaged with a ladle ofmolten metal. The bottom opening and pouring tube are fluidlycommunicable through an ingate assembly that may be pivoted intoairtight engagement with the mold assembly and lowered onto the pouringtube. After molten metal is passed into the mold through the ingateassembly and solidifies, the ingate assembly may be pivoted away fromthe mold assembly thereby breaking the metal in the ingate assembly awayfrom the metal in the bottom opening.

3 Claims, 2 Drawing Figures PATENTEDMAR28 1972 SHEET 1 [1F 2 APPARATUSFOR CASTING METAL ARTICLES This invention relates generally to anapparatus for casting metal articles and more particularly to anapparatus for bottom pressure casting metal articles.

It has been proposed to bottom pressure cast metal articles by placing amovable mold in position over a pouring tube of a conventional bottompressure casting apparatus. After the mold is filled, the flow of metalinto the mold is shut off, the mold is removed from its position overthe pouring tube, and a new mold is moved into position. Each mold isprovided with an ingate assembly which provides communication betweenthe pouring tube and the lower end of the mold. The ingate assemblycarries with it a slide cutoff which is utilized to terminate flow ofmetal into the mold. Such an apparatus is shown in U.S. Pat. No.3,015,863 to C. F. Strorn et al.

The ingate assembly is carried by the mold carriage away from thepouring tank. Operation of this apparatus has been successful. However,one drawback does exist in that the metal between the slide cutoff andthe mold is difficult to remove. It sometimes freezes the ingateassembly to the metal in the mold, which necessitates the use of asledge hammer to remove the ingate assembly. This invariably damages theingate assembly, thereby increasing the cost of the casting operation.

It is, therefore, an object of the present invention to provide a bottompressure casting apparatus wherein the above described difficulties areeliminated.

It is another object of the invention to provide a bottom pressurecasting apparatus with an efficiently operating ingate assembly.

Another object of this invention is to provide an improved ingateassembly.

These and other objects and advantages of this invention will appearfrom a reading of the following detailed description of this inventionwhen taken in conjunction with the accompanying drawings wherein:

FIG. 1 is a side elevational view in cross section of the apparatus ofthis invention, and

FIG. 2 is a front elevational view in cross section of the sameapparatus.

Referring now to the drawings, reference numeral denotes a moldapparatus which is mobile and adapted to be moved on wheels (not shown)into position over a pouring tank 12 of a conventional bottom pressurecasting apparatus. Reference may be had to copending application Ser.No. 382,533, filed July 14, 1964, entitled Casting Apparatus, fordetails of the construction and operation of the mold 10. Since all ofthe details of the construction of the mold 10 are shown in the aboveapplication, all that is required for an understanding of this inventionis a schematic showing of the mold in the drawings. As shown itcomprises a left side block 14, a right side block 16, a bottom block 18and a front end block 20. The top and rear end blocks are not shown.

The mold 10 is positioned with raised ingate assembly 22 over thepouring tube 24 of the tank 12. The pouring tube 24 extends from outsideof the cover 12 and projects into the molten metal 26 contained in theladle 28. As will be described herein, the mold 10, the ingate assembly22, and the pouring tube 24 are placed in sealed relationship with eachother. The molten metal 26 may then be forced upwardly through the tube24, the ingate assembly 22, and into the mold 10 by air pressureproduced in the tank 12 by suitable conventional means (not shown).

The ingate assembly 22 comprises a housing 30 having a cylindricalopening 32 extending therethrough, which receives therein a bushing 34of suitable ceramic material. The housing 30 has a horizontal slot 36extending therethrough to receive a slide or cutoff plate 38. The slide38 is provided with an opening 40 of substantially the same diameter asopening 32. A bushing 42 of suitable ceramic material is positioned inopening 40 and its inner diameter is substantially equal to the innerdiameter of bushing 34. The slide 38 is provided with a solid flatportion 44 which is of greater length and width than the here 46 of thebushing 42. When the slide 38 is activated to shut off flow of moltenmetal through the ingate assembly 22, this portion 44 is moved acrossthe slot 36 to a position covering the bore 48 of the bushing 34,thereby shutting off flow of metal therethrough. Reference may be had tothe aboveidentified patent for details of the construction and operationof slide 38.

The housing 30 of the ingate assembly 22 is constructed in the nature ofa spool having a reduced central portion 50, a radially enlarged upperportion 52, and a radially enlarged lower portion 54. The enlarged upperportion is provided with a substantially flat horizontal under surface56 and the enlarged lower portion 54 is provided with a substantiallyflat horizontal upper surface 58, the function of which will beexplained hereinafter.

On opposite sides of reduced central portion 50 and between flatsurfaces 56 and 58 are positioned two arms 60 of lever mechanism 62. Thetwo arms 60 extend from fulcrum 64, rotatably secured in a conventionalinanner to the main carriage of the mold 10. For example, the fulcrum isrotatably mounted in a bushing 65 retained in an opening 67 of a support69 of the mold carriage. The two ends 66 of the arms 60, remote from thefulcrum 64, are joined together by pin 68. Intermediate the end 66 andthe fulcrum 64, the arms 60 are provided with recesses 70 which receivetherein spring members 72. Each of these spring members 72 rests againstthe flat surface 56 of the upper enlarged portion 52 of the housing 30.The function of these springs will be explained hereinafter. Extendingfrom and secured to fulcrum 64 in the direction opposite that of arms 60is a lever arm 74 whose end 76 remote from the fulcrum 64 is secured toa conventional mechanical screw jack 78. The jack 78 is also carried bythe main carriage of the mold 10.

In operation, the mold 10 is rolled into position over the pouring tube24 .of the tank 12. The jack 78 and lever arm 74 are in the positionshown in full lines in FIG. 1. The springs 72 exert pressure against theflat surfaces 56, forcing the housing 30 upwardly into airtightengagement with the opening 80 of the mold 10. The mold l0 and ingateassembly 22 are then lowered as a unit by a conventional jack or othermechanism (not shown) in order that the ingate assembly may be broughtinto airtight engagement with the pouring tube 24. Pressure is suppliedto the tank 12 to force the molten metal 26 upwardly through the pouringtube 24 into and through the ingate assembly 22 to completely fill themold 10.

After the mold has been filled, the slide cutoff 38 is moved to theright, shutting off flow of metal through the ingate assembly 22. Thepressure in the tank is relieved, permitting the metal in the tube andin the ingate 22 below the slide to return to the ladle 28. The mold isthen raised from the pouring tube 24 and rolled to a remote position forsolidification of the article in the mold. After the article in the moldhas substantially solidified, the jack 78 is activated to raise thelever arm 74 to the dotted line position shown in FIG. 1. This upwardmovement of lever arm 74 causes the fulcrum 64 to rotate in thedirection shown by the arrow in FIG. 1 and brings the arms 60 intoengagement with the flat surfaces 58 of the lower enlarged portion 54.This causes downward movement of the ingate assembly 22 breaking awayfrom the mold opening 80 and stripping that portion of the metal in theingate 22 above the slide cutoff 38.

It can be seen from the foregoing that the operation of the apparatus ofthis invention facilitates removal of the ingate assembly 22 from themold 10 and thereby avoids the difficulties of the prior art devices. Itshould be understood that various modifications may be made in thisapparatus without departing from the spirit and scope of the followingclaims.

I claim:

1. In a gate assembly adapted for use with a bottom pressure castingmachine and through which molten metal passes to the mold assemblycomprising:

a frame,

a gate housing, including a molten metal passageway. and

having one end adapted to be brought into a sealed condition with aportion of the mold,

a carrying arm on said frame freely engaging said housing and projectingaway from one side thereof,

a mechanical self-locking device connected to said arm to verticallydisplace said arm and, hence, move said housing towards and away fromsaid mold assembly,

a power means connected to said device for causing operation of saiddevice,

said power means characterized in having the capacity to at leastmomentarily deliver the required sealing force between said housing andsaid mold assembly, and

wherein said self-locking device has means to maintain said sealingforce on a reduction or discontinuation of the force developed by saidpower means.

2. In a gate assembly according to claim 1 wherein a pair of openings isformed in said housing:

said arm comprising a pair of fingers, one of which extends into one ofsaid housing openings and the other of which extends into the other ofsaid housing openings:

a shaft located on one side of said housing carrying said fingers in amanner that the fingers and the shaft form a three-sided channel intothe open end of which is received said housing; and

means for holding said housing on said arms.

3. In a gate assembly according to claim 1, in which said arm isconnected to said self-locking device by a shaft,

said self-locking device comprising a single screw jack having a gearratio and pitch characteristic so as to hold the arm and, hence, thegate assembly at a force substantially equal to that developed by saidpower means, and

wherein said power means comprises a motor.

1. In a gate assembly adapted for use with a bottom pressure castingmachine and through which molten metal passes to the mold assemblycomprising: a frame, a gate housing, including a molten metalpassageway, and having one end adapted to be brought into a sealedcondition with a portion of the mold, a carrying arm on said framefreely engaging said housing and projecting away from one side thereof,a mechanical self-locking device connected to said arm to verticallydisplace said arm and, hence, move said housing towards and away fromsaid mold assembly, a power means connected to said device for causingoperation of said device, said power means characterized in having thecapacity to at least momentarily deliver the required sealing forcebetween said housing and said mold assembly, and wherein saidself-locking device has means to maintain said sealing force on areduction or discontinuation of the force developed by said power means.2. In a gate assembly according to claim 1 wherein a pair of openings isformed in said housing: said arm comprising a pair of fingers, one ofwhich extends into one of said housing openings and the other of whichextends into the other of said housing openings: a shaft located on oneside of said housing carrying said fingers in a manner that the fingersand the shaft form a three-sided channel into the open end of which isreceived said housing; and means for holding said housing on said arms.3. In a gate assembly according to claim 1, in which said arm isconnected to said self-locking device by a shaft, said self-lockingdevice comprising a single screw jack having a gear ratio and pitchcharacteristic so as to hold the arm and, hence, the gate assembly at aforce substantially equal to that developed by said power means, andwherein said power means comprises a motor.